Hi Yuki, welcome!
We do not use the Subdivision Surface Modifier to smooth out shapes, but if you subdivide a Plane for instance, because you need more Vertices, then that is okay. So it is important how and why you would use that node.
Geometry Nodes was first created for set dressing, so it seems logical to me to use it in our case, but everybody is completely free to use whatever method she/he wants of course!
I’d suggest to use little geometry and textures with an Alpha, to create things like leaves and grass blades, because there will be a lot of them and I don’t want to destroy Kent’s computer 🤣
But we will see how everything goes.
